Feature tracking

[BuckWyckoff]

I haven't quite found what I want in the help.  I saw a MAX tutorial years ago where a plane's corners were tracked so that a video could replace the plane and it stayed locked to the plane as the camera moved around.

I have a white disc (approx 3") that I can put whatever style of markers on it that would work best.  I want to shoot video of my hand holding the disc and moving it around in the video.  I want to replace the disc with a 3D object.  The disc will be tilted all around so the disc plane orientation will have to be tracked over the movie range.

Camera tracking has object pinning, but that seems to be for locking an object to one tracked feature and then moving it around.  Not really detailed orientation in space.

If I draw a black square on my white disk, I want a plane (or one side of a dummy) to lock to the square on the disk and tilt, rotate, move all around matching the video perfectly.

I'm pretty sure that can be done.  Having trouble finding the correct reference material.  Any clues?

Thanks.

Buck Wyckoff

BDSI

[BuckWyckoff]

In this case, I'm going to have a camera locked down on a tripod and I'll be holding a wooden base with the reference grid on the top.  My hand will be moving and rotating and I want to have a CG object locked to the base and my hand movements.  So I'm not looking for a camera match, but tracking an object's orientation in a static camera.

[Steve_Curley]

You could try MatchMover though it sounds more like something a Compositor (like Composite (aka Toxik)) would do (Composite is also available, for free, on the app exachange site).

[BuckWyckoff]

Thanks.

I've been looking at Match Mover.  One tutrial on Lynda.com and it's all about camera solves and exporting to Maya.  I did see that you can choose to animate a camera from the solve, or animate the scene.  The tutorial didn't cover scene exporting, but that may be the solution.

Not sure how compositing would work because I have to render the CG to match the live action.  So to composite I need the CG pre-tracked.  Push comes to shove, I'll manually track it.  I'm going to keep the shot simple, but still....

I like to use holiday projects to learn new techniques.

[tony.su]

Yes， you can try matchmover. It's free now.

https://apps.exchange.autodesk.com/MAYA/en/Detail/Index?id=appstore.exchange.autodesk.com:autodeskma...

Here is tutorial.

https://www.youtube.com/watch?v=DEupMxyGmfg

https://www.youtube.com/watch?v=3L_J8PxVdIQ

[BuckWyckoff]

Nice!

Thanks.

[BuckWyckoff]

Major fail.  Like I said, I have a fixed camera and a moving object that I put a reference grid on.  By setting several keys myself to help it along, I got several good 2D tracks.  But as far as I can tell you can only solve for a camera.  It doesn't like my setup.  I enter corrdinates for the points, the program crashes.  I  load the sequence and let the program auto solve, it crashes.  I set the camera to fixed.  Free. Whatever.  Doesn't matter.

I have generated 2D data that I know will generate a solve, but I can't get there.  And it's a weirdly limbo AutoDesk product with no forum or support.  So.......sucks to be me.

[tony.su]

Matchmover is not an automatic solve software. You should add some correct track point based on the experience. And then solve.

It can solve most shots. Good news is it's free. Bad news is whether it is work or not base on your experience. If you have a lots of experience on camera tracking, you can master it. But if you a beginner, it'll be a little difficulty.

If you upload your shot, I can try it for you.

[BuckWyckoff]

I didn't auto track anything.  I read the entire manual this morning and supervise tracked every trackpoint perfectly (see attached).  The inability for get a solve isn't due to my lack of experience.  There is nothing in the manual or tutorials that even begins to describe the process for a locked down camera situation.  I've exhausted every option in every menu and dialog.

I've been in this game for 25 years and I can wrangle complex software.  The status of MM within AutoDesk clearly leaves a lot to be desired.  I could care less that it's free.  I'd rather pay $500 and enjoy a thriving community than pay $0 and find only forum references from 6-12 years ago.  Boujou is $10K!  I think there's a major opportunity missed here.

[tony.su]

Camera track is a complicated problem. There are some books about it. One of them is Matchmoving: The Invisible Art of Camera Tracking. It is an old book, the software is more power now, but the principle never changed. You can read it.

Camera track is base on math principles. I used 3 whole day taught my student how to use matchmover and boujou. But some of them couldn't understand what I said. They are good at art, but it is maths problem.

Boujou is a good tools too. It can automatically solve least 60% shots(for your shot, need add masks). But it is very expensive, and sometimes you need add some points manually to correct the result. So you need the knowledge about camera track principle too.

Here is my suggestion about your shot.

[BuckWyckoff]

Thanks for the suggestions.  I realize this is a complex topic and people spend a career specializing in it.  I however am doing this for a holiday project that was conceived a week ago and must be finished in the next 7-10 days (several of which will involve rendering).

I guess I figured, if the camera is locked down, then just the reference plane moving can be figured out, but yeah, you still need the correct camera solve.  Luckily, I haven't touched the scene (though the camera in gone).  I'm going to whip out my Faro Arm and digitize many points in the scene; points on the table top, tree, figurines and top corners of the open box.

Maybe I can give these survey points to MM to get a camera solve, then with that solve, look only at the points in the moving referenced plane and solve for that.  If that doesn't work, I don't have time for anything else (though I can track a few points on the "2014" if that helps per your suggestion). 

Push comes to shove, I'll do a camera solve within MAX on te Faro data, 3D model the box, measure and duplicate the snow globe base in MAX with the precise reference grid on top and then manually animate it moving.  It's only a 20 second shot, to I can slog through it if I need to.  With all the knowns, it's doable.

Still, I'd love to get the grid reference points calculated in MM brought into MAX.

Oh well, I do love a challenge.

Thanks for the help.

[tony.su]

ok. If you need help zip your shot and upload, I'll help you.

[BuckWyckoff]

Well, that's generous.  Thanks.

I digitized the scene and got a great MAX camera match.  I looked into using that to set the coordinate system in MM, but it seems like the help was describing using tracks as origin & axis points, whereas mine are just all over the stable part of the scene.  I also knew I needed to tell it to make Z up to match the coordinates I do have, but I couldn't find that, though I swore I saw it somewhere.

I have a Rhino/AutoCAD/MAX files with the digitized points.  The MAX file also has the camera match solve and then I have a MM file with the REF points on the moving object already 2D tracked nicely.

The MAX file shows the points in the CM solve aligned with the same background plate used in MM.  I think MAX is the only place where you could see the realtionship between my dig points, what feature they align with in the background plate (via looking through the MAX solved camera and seeing where those points lie), then, for the points chosen for use in MM, quering those points in MAX to get the surveyed XYZ for that point.

Can you work with MAX as well?

Thanks again.

[BuckWyckoff]

What sounds like a nice and easy solution would be to bring in the MAX solved camera for that scene into MM.  With that fixed camera predefined for MM, then just solve the moving object points I already 2D tracked.

Sounds easy.  Not sure if any of that is possible.